Cancer is characterized by uncontrolled cell growth, and such abnormal cell growth forms a mass of cells called a tumor, which penetrates into surrounding tissues, and, in severe cases, causes metastasis into other organs of the body. Academically, tumors are called neoplasia. Cancer affects all tissues and organs of the body at various prevalence rates.
Since the incidence of breast cancer is gradually increasing due to the improvement of living standards owing to economical growth, changes and westernization of eating habits, changes of childbirth and breastfeeding methods, and the like, breast cancer takes first place among female tumors (Kamangar F., et al., 2006). Breast cancer is a malignant tumor that can spread to other organs to threaten ones' life, unlike benign tumors staying in the breast. The beast cancer including metastatic breast cancer to solid tumors has a wide variety of biological characteristics, and thus has various therapeutic options and prognoses.
Although recent developments of radical excision, chemotherapy, and hormone therapy have significantly improved the treatment results of breast cancer, breast cancer recurs in approximately 25-30% of patients without axillary lymph node metastasis and approximately 75-80% of patients with axillary lymph node metastasis within 10 years, and most of these patients die from metastatic breast cancer. As the number of breast cancer patients steadily increases, patients with metastatic breast cancer are also increasing, and therefore, research continues on early breast cancer patients as well as treatment methods of these patients, prognosis, and factors affecting the prognosis, but the results are yet insignificant.
Therefore, with respect to breast cancer treatment, there is a continuing need for the development of therapeutic agents having excellent anti-cancer effects regardless of the presence or absence of breast cancer metastasis.
The present inventors have already received patent rights of technical features wherein tetraarsenic hexoxide purified from natural arsenolite containing arsenic through separation and purification techniques showed cancer metastasis suppressing effects in animal experiments and had excellent anticancer treatment effects when administered to end-stage cancer patients with uterine cancer, bladder cancer, lung cancer, maxillary sinus cancer, kidney cancer, and the like (Korean Patent No. 272835).
The present inventors, as a result of continuous research on arsenic, revealed that tetraarsenic hexoxide having 99% or more of tetraarsenic hexoxide crystalline polymorph a can be produced by a novel preparation method, different from the method disclosed in the above registered patent, and a composition containing such tetraarsenic hexoxide has a remarkable effect on breast cancer prevention or treatment, and completed the present invention.